I. Field of the Invention
This invention lies in the field of cataract surgery and in particular relates to the enzymatic treatment of cataracts followed by removal of the enzymatically digested cataractous material.
II. Background
The lens is an optically clear encapsulated disc-like structure which is suspended within the eye, behind the iris and in front of the vitreous. It supplies part of the optical refracting power of the eye. The lens becomes cataractous when its nuclear and/or cortical and/or subcapsular regions become opaque, thus blocking the path of light entering the eye, thereby causing diminished vision. A cataractous lens (hereinafter identified as cataract) is simply a lens that has become cloudy.
For further background to this invention and for more detailed discussion of the rationale of liquefying a lens enzymatically, reference is made to Ser. No. 660,873 filed Feb. 24, 1973. Suffice it to point out here that surgical techniques for removing cataracts are not entirely satisfactory to patient and surgeons.
The object of this invention is to provide a procedure which eliminates much, if not all, of the hazards and trauma involved in the heretofore known surgical procedures for removing cataracts.
A further object of this invention is to provide certain active proteinases capable of enzymatic digestion of cataractous lens tissue in vivo.